ALBERT

Beschreibung: Losses associated with stem end rot (SER) of avocado fruits have been reported in all avocado growing regions of the world. In Kenya, mature avocado fruits present SER symptoms during storage and marketing, but the disease causal agent(s) has not been established. This study aimed to identify the fungal pathogen(s) associated with avocado SER in Kenya and evaluate its pathogenicity. Fungal isolates were collected from symptomatic avocado fruits from randomly selected orchards and major markets within Murang'a County, a major avocado growing region in Kenya, between September 2017 and March 2018. A total of 207 and 125 fungal isolates, recovered from orchards and major markets, respectively, were identified morphologically and further confirmed by molecular techniques. The identified isolates were Lasiodiplodia theobromae (39.8%), Neofusicoccum parvum (24.4%), Nectria pseudotrichia (18.4%), Fusarium solani (7.2%), F. oxysporum (5.1%), F. equiseti (3.9%), and Geotricum candidum (1.2%). Geotricum candidum was exclusively recovered from fruits from the market. In the pathogenicity test, L. theobromae, N. parvum, and N. pseudotrichia caused the most severe SER symptoms. Consequently, they were considered to be the major pathogens of SER of avocado fruits in Kenya. To our knowledge, this is the first report of SER pathogen of avocado fruits in Kenya. Given the significant contribution of avocado fruits to household income and foreign exchange in Kenya, this information is significant to further develop management strategies of postharvest loss of avocado fruits in Kenya.

Beschreibung: People with noninsulin-dependent diabetes mellitus are prone to urinary tract infections. There is a wide gap of information in developing countries regarding the sociodemographic factors linked to UTI among diabetics and the gender disparity among the same. Sociodemographic factors differ with geographical location and many other factors, and this makes them an important aspect that can influence the social burden of UTI among diabetics. The objective of this study was to determine the association between sociodemographic factors and UTI among diabetics. The study was carried out in the Kisii Teaching and Referral Hospital in Kenya. One hundred and eighty diabetic patients were enrolled in cross-sectional study design. Clean-catch midstream urine was collected from all participants and cultured in cysteine lactose electrolyte deficient agar for bacterial isolation. Classification of a positive culture for urinary tract infection was based on more than 100,000 (≥105) colony-forming units of a single bacterial species. The data were analyzed using frequencies, chi-square (p

Beschreibung: Seed treatment with chemical pesticides is commonly used as an initial plant protection procedure against pests and diseases. However, the use of such chemicals may impair the survival and performance of beneficial microorganisms introduced via inoculants, such as the plant growth-promoting bacterium Azospirillum brasilense. We assessed the compatibility between the most common pesticide used in Brazil for the treatment of maize seeds, composed of two fungicides, and one insecticide, with the commercial strains Ab-V5 and Ab-V6 of A. brasilense, and evaluated the impacts on initial plant development. The toxicity of the pesticide to A. brasilense was confirmed, with an increase in cell mortality after only 24 hours of exposure in vitro. Seed germination and seedling growth were not affected neither by the A. brasilense nor by the pesticide. However, under greenhouse conditions, the pesticide affected root volume and dry weight and root-hair incidence, but the toxicity was alleviated by the inoculation with A. brasilense for the root volume and root-hair incidence parameters. In maize seeds inoculated with A. brasilense, the pesticide negatively affected the number of branches, root-hair incidence, and root-hair length. Therefore, new inoculant formulations with cell protectors and the development of compatible pesticides should be searched to guarantee the benefits of inoculation with plant growth-promoting bacteria.

Beschreibung: The occurrence of carbapenem-resistant (CR) strains of Acinetobacter baumannii is reported to contribute to the severity of several nosocomial infections, especially in critically ill patients in intensive care units. The present study aims to determine the antibiotic susceptibility, clonality, and genetic mechanism of carbapenem resistance in twenty-eight Acinetobacter baumannii isolates from four hospitals in Washington DC. The antibiotic susceptibility of the isolates was determined by VITEK 2 analyses, while PCR was used to examine the presence of antibiotic-resistant genes and mobile genetic elements. Trilocus multiplex-PCR was used along with pulsed-field gel electrophoresis (PFGE) for strain typing and for accessing clonal relationships among the isolates. Antimicrobial susceptibility testing indicated that 46% of the isolates were carbapenem-resistant and possessed MDR and XDR phenotypes. PFGE clustered the 28 isolates into seven clonal (C1–C7) complexes based on 〉75% similarity cut-off. Thirty-six percent of the isolates belonged to international clone II, while 29% were assigned to Group 4 by trilocus multiplex-PCR. Although the blaOXA-51-like gene was found in all the isolates, only 36% were positive for the blaOXA-23-like gene. PCR analysis also found a metallo-β-lactamase (MBL) gene (blaVIM) in 71% of the isolates. Of the 13 CR isolates, 8 were PCR positive for both blaVIM and blaOXA-23-like genes, while 5 harbored only blaVIM gene. This study revealed the emergence of VIM carbapenemase-producing A. baumannii isolates, which has not been previously reported in the United States.

Beschreibung: Background. In most African countries including Ethiopia, Neisseria gonorrhoeae infections were diagnosed clinically and its antibiotic susceptibility was rarely tested. This study aimed to determine the prevalence and antimicrobial susceptibility patterns of N. gonorrhoeae among suspected patients attending private clinics in Jimma, Ethiopia. Methods. Institution-based cross-sectional study was conducted to determine the prevalence and antimicrobial susceptibility pattern of N. gonorrhoeae isolated from urogenital specimens. Urogenital samples were collected aseptically and then transported using Amie’s transport media and processed in a microbiology laboratory following the standard protocol. Results. Of the total 315 samples examined, 31 (9.8%) were confirmed to have gonococcal infection. Of these, 30 (96.7%) were females. High proportion of culture confirmed cases (18 (12.5%)) were observed in the 20–24 age group. All of the identified organisms were susceptible to ceftriaxone and had high resistance to penicillin (80.6%) and tetracycline (54.8%). Conclusion. The prevalence of gonococcal infection is high. In the current study, participants who have no information about sexually transmitted infection were more likely to be infected by N. gonorrhoeae. According to our study, ciprofloxacin is effective against gonococcal infection.

Beschreibung: Thermophilic Campylobacter species are clinically important aetiologies of gastroenteritis in humans throughout the world. The colonization of different animal reservoirs by Campylobacter poses an important risk for humans through shedding of the pathogen in livestock waste and contamination of water sources, environment, and food. A review of published articles was conducted to obtain information on the prevalence and antimicrobial resistance (AMR) profiles of thermophilic Campylobacter species in humans and animals in sub-Saharan Africa (SSA). Electronic databases, namely, PubMed, Google Scholar, Research4life-HINARI Health, and Researchgate.net, were searched using the following search terms “thermophilic Campylobacter,” “Campylobacter jejuni,” “Campylobacter coli,” “diarrhea/diarrhoea,” “antimicrobial resistance,” “antibiotic resistance,” “humans,” “animals,” “Sub-Saharan Africa,” and “a specific country name.” Initially, a total of 614 articles were identified, and the lists of references were screened in which 22 more articles were identified. After screening, 33 articles on humans and 34 on animals and animal products were included in this review. In humans, Nigeria reported the highest prevalence (62.7%), followed by Malawi (21%) and South Africa (20.3%). For Campylobacter infections in under-five children, Kenya reported 16.4%, followed by Rwanda (15.5%) and Ethiopia (14.5%). The country-level mean prevalence in all ages and under-five children was 18.6% and 9.4%, respectively. The prevalence ranged from 1.7%–62.7% in humans and 1.2%–80% in animals. The most reported species were C. jejuni and C. coli. The AMR to commonly used antimicrobials ranged from 0–100% in both humans and animals. Poultry consumption and drinking surface water were the main risk factors for campylobacteriosis. The present review provides evidence of thermophilic Campylobacter occurrence in humans and animals and high levels of AMR in SSA, emphasizing the need for strengthening both national and regional multisectoral antimicrobial resistance standard surveillance protocols to curb both the campylobacteriosis burden and increase of antimicrobial resistance in the region.

Beschreibung: Traditional small-scale gold mining mostly use mercury to extract the gold from ores. However, mercury contamination in the environment can affect the composition and structure of the bacterial community. The purpose of this study was to determine the effect of mercury contamination on the bacterial community in the traditional gold mining waste disposal site and in the rice field. Mercury analysis was carried out using the CVAFS method. Analysis of bacterial communities and structure was carried out based on the results of metabarcoding of the V3-V4 16S rRNA regions obtained from paired-end Illumina MiSeq reads. The results showed that the sample from the mining waste disposal site had a mercury level of 230 mg/kg, while the sample from the rice field had 3.98 mg/kg. The results showed that there were differences in microbial composition and community structure in both locations. With the total reads of 57,031, the most dominant phylum was Firmicutes in the mining disposal site sample. Meanwhile, with the total reads of 33,080, the sample from rice field was dominated by Planctomycetes. The abundant classes of bacteria in the mining waste disposal site, from the highest were Bacilli, Gammaproteobacteria and Planctomycetia, while the sample from the rice field was dominated by the Planctomycetia and Acidobacteria subdivision 6. The families that dominated the sample in disposal site were Bacillaceae and Aeromonadaceae, while the sample from the rice field was dominated by Gemmataceae. The abundant genera in both locations were Bacillus and Gemmata. This study concluded that the high level of mercury in the soil reduced the richness and diversity of bacterial phyla and lower taxa. There was also a shift in the dominance of phyla and lower taxa in both locations. This study provides an understanding of the microbial community structure in the area that is highly contaminated with mercury to open insight into the potential of these bacteria for mercury bioremediation.

Beschreibung: This study reports on the isolation and identification of Methylobacterium radiotolerans MAMP 4754 from the seeds of the medicinal plant, Combretum erythrophyllum, for the purposes of investigating antimicrobial and antioxidant activities from this endophyte. The strain identity was confirmed by 16S rRNA-based phylogeny and Scanning Electron Microscopy (SEM). Ethyl acetate and chloroform (1 : 1 v/v) extracts from the endophyte were tested for antimicrobial and antioxidant activity on a total of 7 bacterial species (3 Gram-positive and 4 Gram-negative) using the standard Minimum Inhibitory Concentration (MIC) protocol and Quantitative Radical Scavenging activity using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay, respectively. The MICs were recorded at 250 μg/mL for B. subtilis ATCC 19659, B. cereus ATCC 1076, E. coli ATCC1053, and 62.5 μg/mL for K. oxytoca ATCC 13182 and M. smegmatis ATCC 21293, while an IC50 of 5.65 μg/mL was recorded with the DPPH assay. Qualitative phytochemical analysis was positive for alkaloids, flavonoids, and steroids. Gas chromatography/mass spectrometry (GC/MS) analysis revealed the presence of 9-octadecene, 2,4-dinitrophenyl acetate, and 2(5H)-furanone, which have been previously reported for the targeted activities. M. radiotolerans MAMP 4754 tested positive for antimicrobial and antioxidant activity and this is linked to the production of plant-derived secondary metabolites by this strain.

Beschreibung: Many developing countries depend on herbal mixtures as the first line and cost-effective therapy for malaria. These mixtures with such curative tendencies may also be a source of toxicity to host cells. On the other hand, these mixtures may have anticancer potential activity characterized by cytotoxicity to cancer cells. The aim of the study was to determine the cytotoxic and antioxidant effects of five different antimalarial herbal mixtures. Five antimalarial herbal mixtures commonly used in Ghana (coded as STF, SMH, SMM, SGM, and STT) were purchased and freeze-dried. The dried samples were tested on human acute T-cell leukemia (Jurkat) and breast adenocarcinoma (MCF-7) cell lines. Cytotoxicity was assessed using the tetrazolium-based colorimetric (MTT) assay while antioxidant activity was determined using DPPH free-radical scavenging assay. Among the mixtures, SMM and SGM exhibited the strongest cytotoxicity towards Jurkat cells (IC50 values 59.17 μg/ml and 49.57 μg/ml, respectively), whereas STT showed the weakest cytotoxicity (IC50 = 244.94 μg/ml). Cytotoxic effect of SMM was also strongest towards MCF-7 cells whilst the least cytotoxic sample was SGM (IC50 〉 1000 μg/ml). SMM had the highest antioxidant percentage (EC50 = 1.05 mg/ml). The increasing order of antioxidant percentage among the five herbal mixtures is SMM 〉 SMH 〉 STT 〉 STF 〉 SGM. The herbal mixtures may be potential sources of toxic agents to host cells. Therefore, further toxicity studies must be performed to safeguard health of the public. Interestingly, cytotoxicities exhibited by SMM and SGM suggest the presence of anticancer constituents in them which warrant further studies.

Beschreibung: Proteus mirabilis is the third most common bacterium that can cause complicated UTI, especially in catheterized patients. Urovirulence genes of P. mirabilis strains are poorly identified among UTI patients. The aims of the present study were to determine the prevalence of the uropathogenic P. mirabilis strains isolated from UTI patients by the detection of several P. mirabilis virulence genes and to characterize the antibiotic susceptibility profile of P. mirabilis isolates. P. mirabilis isolates were collected from urine specimens of patients suffering from UTI. Virulence genes in P. mirabilis, namely, hpmA, hpmB, rsbA, luxS, ureC1, hlyA, rpoA, atfA, atfC, mrpA, and pm1 were detected in the isolates via PCR detection method. All P. mirabilis virulence genes were detected in more than 90% of the isolates except hlyA gene, which was detected in only 23.8% of the isolates. The rate of susceptibility for ceftriaxone was 96.8%, followed by norfloxacin (82.5%), gentamicin (71.4%), ciprofloxacin (69.8%), cephalexin (52.4%), nalidixic acid (42.9%), sulfamethoxazole (39.7%), ampicillin (36.5%), and nitrofurantoin (3.2%). Significant associations () were detected between antimicrobial susceptibility of each of the following antibiotics and the presence virulence genes. Cephalexin antimicrobial susceptibility was significantly associated with the presence each of ureC1 and atfC. Sulfamethoxazole antimicrobial susceptibility was significantly associated with the presence atfA. Ceftriaxone antimicrobial susceptibility was significantly associated with the presence each of hpmA, ureC1, rpoA, atfC, mrpA, and pm1. Nitrofurantoin antimicrobial susceptibility was significantly associated with the presence each of hpmA, ureC1, rpoA, atfA, atfC, mrpA, and pm1. In conclusion, an association between the presence of urovirulence genes of P. mirabilis and increasing P. mirabilis resistance to antimicrobials has been demonstrated.